unordered_set count() in C++

count(): This function is available in the File: unordered_set.h

Syntax:

std::size_t std::unordered_set<int>::count(const int &__x) const

This function takes an argument of type int as its parameter. This function finds the number of elements with the specified key.

Parameters: One parameter is required for this function.

__x – Element to located.

Returns: Number of elements with the specified key. This function only makes sense for unordered_multisets; for unordered_set the result will either be 0 (not present) or 1 (present).

For Example:

st = {9.4}

x = 4

st.count(x) => It returns 1.

Approach

C++

#include <bits/stdc++.h>
using namespace std;

int main()
{
    unordered_set<int> st;
    st.insert(9);
    st.insert(4);

    int x = 4;
    cout << st.count(x) << "\n";

    return 0;
}

Output:

1